Lubricating oil thickened to a grease with a 1, 3, 5-triazine compound



UnitedStates Patent Ofifice 3,160,501 Patented Dec. 8, 1054 This invention relates to an improved lubricating composition and more particularly to a lubricant suitable for high temperature lubrication.

The trend in design of modern aircraft has accentuated the need for greases which will lubricate antifriction bearings operating at high rotational speeds and high temperatures. Considerable progress has been made operating at speeds of 10,000 to 20,000 and more revolutions per minute and'temperatures of about 400 to about600 F. for prolonged periods of time.

We have discovered that a lubricating composition having improved lubricating characteristics for an extended period of time when used to lubricate bearings 'opearting at temperatures up to about 600 F. and speeds of 10,000 to 20,000 and more revolutions per minute can be obtained by incorporating into a lubricating oil in oil thickening proportions a symmetrical triazine, i.e;,

:a 1,3,5-triazine compound melting above about 400 F.

(205 C.) having the following formula:

wherein R and R are selected from the group consisting of hydrogen, alkyl, aryl, alkaryl, aralkyl, cyanoalkyl, pyridyl, amino, hydroxy and mercapto radicals, R and R being unlike radicals when selected from the group consisting of amino, hydroxy and mercapto radicals. Thus, the improved lubricating composition of the present invention consists of a dispersion in a lubricating oil of a suflicient amount to thicken the lubricating oil to a grease consistency of al,3,5-triazine compound melting above about 205 C. of the type designated by the above structural formula. The lubricating composition of the invention can contain one or more of the triazine compounds. Especially preferred compositions consist of a lubricating oil thickened to the consistency When a mixture of ammeline pyridyl radicals provided, of course, that the melting point of the compound is at least 205 C. When R and R are selected from the group consisting of amino, hydroXy and mercapto radicals, the radicals should not all be the same. For example, we do not intend to include compounds such as cyanuric acid (s-triazinetriol) or melamine (2,4,6-triamino-s-triazine).

It should be understood that the symmetrical (s) triazine compounds can contain other substituents provided, of course, that said other substituents do not adversely affect the beneficial oil thickening properties of the s-triazine compounds.

An especially preferred group of triazine compounds for the purpose of the invention includes those compounds wherein each of the R radicals is'either -a hydroxy radical or an amino radical. When each of the R radicals is an amino radical, the resulting compounds are designated as guanamine derivatives. Preferred guanamine derivatives are those wherein R is selected from the group consisting of hydrogen, alkyl (e.g., methyl, ethyl, propyl and n-butyl), aryl (e.g., phenyl and naphthyl), alkaryl (eg, tolyl), aralkyl (e.g., benzyl), cyanoalkyl (e.g., cyanoethyl, cyanobutyl and cyanooctyl), pyridyl, hydroxy and mercapto radicals. When R in the guanamine derivatives is an alkyl radical, it preferably is selected from the group consisting of methyl, ethyl, propyl and n-butyl radicals in order to give a compound having a melting point above about 205 C. When R is isobutyl or a higher alkyl radical the melting point of the resulting substituted guanamine is below 205 C. While compounds melting below 205 C. can be used to produce grease compositions for use at temperatures below 400 R, such compounds are not Illustrative of the preferred guanamine derivativeswhich can be used in the present invention are the followmg:

2,4-diamino-l,3,5-triazine 2,4-diamino-6-methyl-1,3,5-triazine 2,4-diamino-6-ethyl-1,3,5-triazine 2,4-diamino-6-propyl-1,3,5-triazine 2,4-diamino-6-n-butyl-1,3,5-triazine 2,4-diamino-6-phenyl-1,3,5-triazine 2,4-diamino-6-a-naphthyl-1,3,5-triazine 2,4-diamino-6-fi-naphthyl-1,3,5-triazine 2,4-diamino-6-m-tolyl-l ,3 ,5 -triazine 2,4-diam no-6-p-tolyl-1,3,5-triazine 2,4-diamino-6 benzyl-1,3,5-triazir1e 2,4-diamino-6-cyanoethyl-1,3,5-triazine 2,4-diamino-6-cyanobutyl-1,3,5-triazine 2,4-diamino-6-cyanooctyl-1,3,5-triazine 2,4-diamino-6-pyridyl-1,3,5-triazine 2,4-diamino6-hydroxy- 1,3,5 -triazine 2,4-diamino-6-mercapto-1,3,5-triazine I may be employed.

While the guanamine derivatives of the above type are all effective thickeners for the preparation of 'high temperature greases, it is not to be implied that all serve with equal efiiciency, since the various compounds may vary to some extent depending upon the nature and severity of the service to which they are subjected. That guanamine derivative which contains a hydroxy radical, i.e., 2,4-diamino-6-hydroxy-1,3,5-triazine (amrneline) is an especially preferred compound for use in the grease composition of the present invention.

The 1,3,5-triazine compounds can be prepared according to known chemical procedures. Neither the compounds per se nor their preparation constitutes any portion of the invention. For example, a 2-amino-4,6-dialkyl-1,3,5-triazine can be prepared by reacting a nitrile with guanidine. A 2,6diamino-4-alkyl-1,3,5-triazine can be prepared by reacting alkyl biguanides with acylating agents in the presence of alkali. Acetoguanamine (2,4-diamino-6-methyl-1,3,5-triazine) having a melting point of 271 to 273 C. can be prepared by reacting dicyandiamide and acetonitrile in the presence of piperidine. Benzoguanamine (2,4-diamino-6-phenyl-1,3,5-triazine) having a melting point of 222 C. can be prepared by reacting dicyandiamide and benzonitrile in the presence of piperidine. 2,4- diamino-6-(2'-naphthyl)-1,3,5-triazine having a melting point of 240 C. can be prepared by reacting beta-naphthonitrile and dicyandiamide in the presence of piperidine. 2,4-diamino-6-benzyl-1,3,5-triazine having a melting point of 232 C. can be prepared by reacting dicyandiamide and benzylcyanide in the presence of piperidine. The preparation of some of the 1,3,5-triazines is more fully described in US. Patent No. 2,527,314, issued October 24,

1950 to Iohnstone S. Mackay; US. Patent No. 2,302,162,

issued November 17, 1942, to Werner Zerweck et al.; and U.S. Patent No. 2,408,694, issued October 1, 1946 to John Kenson et al.

The amount of the 1,3,5-triazine compound which we use is an amount suflicient to thicken the lubricating oil to a grease consistency. The exact amount in terms of weight percent may vary over wide limits depending upon the particular oil with which the triazine compound is to .be blended and upon the properties desired in the final lubrication composition. While as much as 45 percent by weight of the total composition may comprise the triazine compound, we prefer to use smaller amounts, that is, in the order of about 20 to about 40 percent by weight. It should be understood, however, that, depending upon the consistency of the composition desired less than 20 percent or more than 45 percent of the triazine compound In general, however, the 1,3,5-triazine compound comprises about 20 to about 45 percent by weight of the total composition.

The lubricating oil in which the .triazine compound is incorporated is preferably a lubricant of the type best suited for the particular use for which the ultimate composition is designed. Since many of the properties possessed by the lubricating oil are imparted to the ultimate lubricating composition, we advantageously employ an oil which is thermally stable at the contemplated lubricating temperature. Some mineral oiis, especially hydrotreated mineral oils, are sufiiciently stable to provide a lubricating base for preparing lubricants to be used under moderately elevated temperatures. In general, however, where temperatures in the order of 400 to 600 F. are encountered, synthetic oils form a preferred class of lubricating bases because of their high thermal stability. The synthetic oil can be an organic ester which has a majority of the properties of a hydrocarbon oil of lubricating grade such as di-2-ethylhexyl sebacate, dioctyl phthalate and dioctyl azelate. instead of an organic ester, we can use polymerized olefins, copolymers of alkylene glycols and alkylene oxides, polyorgano siloxanes, polyaryl ethers and the like. I

The liquid polyorgano siloxanes and certain polyaryl ethers because of their exceedingly high thermal stability form a preferred group of synthetic oils to which the triazine compound is added. The polyorgano siloxanes are known commercially as silicones and are made up of silicon and oxygen atoms wherein the silicon atoms may be substituted with alkyl, aryl, alkaryl, aralkyl and cycloalkyl radicals. xemplary of such compounds are the dimethyl silicone polymers, diethyl silicone polymers, ethyl-phenyl silicone polymers and methyl-phenyl silicone polymers. Exemplary of the polyaryl ethers are the polyphenyl ethers, i.e., m-bis(m-phenoxyphenoxy) benzene and m-bis(m-phenoxyphenoxy) phenyl ether.

If desired, a blend of oils of suitable viscosity may be employed as the lubricating oil base instead of a single oil by means of which any desired viscosity may be secured. Therefore, depending upon the particular use for which the ultimate composition is designed, the lubricating oil base may be a mineral oil, a synthetic oil, or a mixture of mineral and/or synthetic oils. The lubricating oil content of the compositions prepared according to this invention comprises about 55 to about percent .by weight of the total composition.

In compounding the compositions of the present invention, various mixing and blending procedures may be used. In a preferred embodiment of the invention, the lubricating oil and the triazine compound together with conventional lubricant additives, if desired, are mixed together at room temperature for a period of about 10 to 30 minutes to form a slurry. During this initial mixing period some thickening is evidenced. Some lumps may be formed. The slurry thus formed is then subjected to a conventional milling operation in a ball mill, a colloid mill, homogenizer or similar device used in compounding greases to give the desired degree of dispersion. In the illustrative compositions of this invention, the slurry was passed twice, by means of a pump, through a Premier Colloid Mill set at a stator-rotor clearance of 0.002 inch. Maximum thickening occurred on the second pass through the mill.

7 The lubricating composition of this invention can contain conventional lubricant additives, if desired, to improve other specific properties of the lubricant without departing from the scope of the invention. Thus, the lubricating composition can contain a filler, a corrosion and rust inhibitor, an extreme pressure agent, an antioxidant, a metal deactivator, a dye and the like. Whether or not such additives are employed and the amounts thereof depend to a large extent upon the severity of the conditions to which the composition is subjected and upon the stability of the lubricating oil base in the first instance. Since the polyorgano siloxanes, for example, are in general more stable than mineral oils, they require the addition of very little, if any, oxidation inhibtor. When such conventional additives are used they are generally added in amounts between about 0.01 and 5 percent by weight based on the weight of the total composition.

In' order to illustrate the lubrating characteristics of grease compositions of the invention when used to lubricate bearings operating at 400 to 600 F. and at rotational speeds or" 10,000 to 20,000 and more revolutions per minute, a slight modification of the test procedure outlined by the Coordinating Research Council Tentative Draft (July 1954), Research Technique for the Determination of Performance Characteristics of Lubricating 'Grease in Antifriction" Bearings at Elevated Temperatures, CRC Designation L-35 was used. According. to the CRC L35 test method, the test bearings are packed with 3.5 cc (or equivalent weight) of grease. Because of the extremely short life of bearings packed with 3.5 cc of grease, the present evaluations were made by packing 'the bearings completely full with about 6 to 8 grams of grease and using either a standard end cap with no additional grease or a special end cap holding a reservoir of about 10 grams of additional grease. In some tests in the High Speed Testers which normally employ only 3.5

cc. of grease, the cavities inside the shields are packed with 4.5 grams of additional grease. The bearing assembly containing an eight-ball SAE No. 204 ball bearing is mounted on a horizontal spindle and in all tests except in 6 The long performance life of the composition of the invention at high rotational speeds and high temperatures is self evident from the above data.

In order to illustrate further the improved lubricating the High Speed Testers is subjected to a radial load of 5 characteristics of a grease composition of the invention, 5 pounds. In the High Speed Testers, a radial load of a composition (Composition B) similar to Composition 16 pounds is employed. The portion of the spindle upon A was prepared employing a synthetic oil known as QF- which the test bearing aseembly is located is encased in a 67039 Fluid. QF-6-7039 Fluid is marketed by Dowthermostatically controlled oven. By this means the tem- Corning Corporation and is believed to be a methylphenperature of the bearing can be maintained at a desired 10 ylsiloxane polymer inhibited against deterioration and elevated temperature. The spindle is driven by a constant otherwise similar to QF-6-7024. The thickened lubricabelt-tension motor drive assembly, capable of giving spinting compositions using QF6+7039 had the following apdle speeds up to 45,000 revolutions per minute. The proximate make-up and properties.

spindle is operatedon a cycling schedule consisting of a series of periods, each period consisting of 20 hours run- Table H ning time and 4 hours shutdown time. The test con- A Tinues until the lubricant fails. The lubricant is conggijf gg g g 2 f B g o Q1-6 7039 65 sldered to have falled when any one of the followmg Ammeline 35 conditions occurs, (1) spindle input power increases to Inspection.

a value approximately 300 per cent above the steady state Penetllation (ASTM D217 52T) condition at the test temperature; (2) an increase in tem- Unworked 272 perature at the test bearing of 20 F. over the test tem- Worked f 275 Feature during any 119M011 cycle; or the t Dro in eaj 9i1rans5a153:I: 830+ or the drive belt snps at me start or durmg Performance life hrs; 0

The lubricating oil used in preparing the lubricating i n composition shown in Table I was a synthetic oil known ZOOOOI 155 as QF-6-7024 Fuild marketed by Dow-Corning Corpora- 36060 at F 1509+ tion. This fluid is considered to be a methyl-phenylsi- 45000 at 2 149 loxane polymer wherein the end silicon atoms are sub- 1 stitnted to a high degree by two phenyl groups and one High speed tester. gg fi gggg gfi fig i z gigi g gii The long performance life of the composition of the inviscosity at 100 F. of about 930 to 1030 SUS, a viscosity Vianuon (comp Gait-1 on at high rota'nonal eeds a at 210 F. of about 90 to 100 SUS, a viscosity index of high temperatures 1s readily apparent from an mspection about 108 to 110 and a pour point or" +10 to +20 F. of h data m Table h l b In preparing the lubricating composition, the oil and k and Properties Ct u nca-tmgicomfl the ammdine were mixed at room temperature for a posltions wnhm the scope of Tghemventron are 1llustrated period of 10 to 30 minutes. The slurry thus formed was' m Table The D 550 lmd used i cgmposmlms passed twice through a Premier Colloid Mill set at a stator- 40 and 1S f i by i i i rotor clearance of 0.002 inch. The thickened lubricating and 1S a tntthylpkenylslbxafie E i avmg as typ 1C composition thus prepared had theiollowing approximate cilaraitenstlcs Vlscoslty at 00 to a makeup and properties v1scos1ty-temperature coeflic1ent of 0.73, a freezmg pomt of 54 F., a flash point of 600 F. and a specfiic gravity Table I 25 C./25 C. of'1.08. The bis(phenoxy-phenoxy) bencomposifiion Parcent by Weight: 1 A zene used in Composition l'consists of a mixture of iso- Lubricating l, IDCI'S thereof having as typical Chai'aCtfl JSUCS a VlSCOSlty Ammeline 35 at 100 F. of about 1691 SUS, a v1scos1ty at 210 F. of Inspection: about 70.8 SUS and a pour point of +40 F. The n-b1s Penetration (ASTM D217 52T): V (m-phenoxyphenoxy)phenyl ether used m Compositions Unworked 396 I, K and L has as typlcal characteristics a viscosity at Worked 306 100 F. of about 8565 SUS, a viscosity at 210 F. of Dropping point, 0 R (ASTM B56542) 900+ about 118 SUS and apour point of +70? F. Composi- Performance life, hrs: trons C to 0 were sub ected to a test usmg' Pope spindles 10 000 1pm. at 00 F 93 55 and an MRC 2043-17 hearing at 600 F. and 20,000 16V- 20000 at 400 F 7 olntions per minute. In these tests the bearings were 20 000 1pm at 500 F 455 packed with 7 to 8 grams of grease. A special end cap 20,000 1,P m at 600 F 102 holding about 10 grams of additional grease was also em- 20,000 r.p.m. at 700 F 49 p y Table III Composition, Percent By Weight 0 D E F G H I J L M N O Lubricating Oil:

Do 550 Fluid so 32.5 QF67 2 32.5 00 72 4s. 75 s5 65 heno )ben ne n 16 25 n 70 -Binmh eiiox iiimox hen lether I: III: "72" "05" "00 III: 1,3,5-Triazine Compound:

Ammeline (2,4-rliamino-6-hydroxy-l,3,5-triazine) 40 35 35 40 2s 20 35 2s 35 40 17.5 Arrunelide (2,4-dil1ydroxy-6 amino-1,3,5-triazine) 35 17.5 30 mspectio'm TM 1321 -521 %;1 i7f' 0 1 i (e L I i 309 351 324 272 335 392 291 355 328 287 362 335 351 Worked 343 366 295 265 332 381 275 343 317 291 358 921 339 Dropping Point,1-. (ASTM 13566-42) 900+ 800+ 900+ 900+ 900+ 900+ 900+ 900+ 900+ 900+ 900+ 900+ 850+ Performance Life, hrs, 20,000 r.p.rn at 600 F s5 91 97 81 103 79 7e 70 96 78 117 105 77 I 7 The long penformance life of compositions of the invention is readily apparent from an inspection of the data in Table 111.

Other lubricating compositions within the scope of the 8 wherein R is selected from the group consisting of hydrogen, alkyl, aryl, alkaryl, aralkyl, cyanoalkyl, pyridyl, hydroxy and mercapto radicals.

V 6. The lubricating composition of claim 5 wherein the lubricating oil is a polyorgano siloxane.

invention are illustrated in Table IV. a

Table IV Composition, Percent By Weight P Q R s T U V W X Y Z A B D Lubricating Oil:

DC 550 Fluid, 6O 65 70 75 80 QF-6-7024 60 65 70 75 so 60 65 70 75 so Di-2ethulhexyl sebacate 1,3,5-Triazine Compound:

Benzoguanamine (2,4-diami11o-6-phenyl-1,3,5

triazine) Ammelide (2,4-dihydroXy-6-amino-1,3,5-

triazine) Ammeline (2,4diamino-6-hydroxy-1,3 triazine) 2,4-Dihydroxy-6-pyridyl-l,3,5-triaxin 2,4Dimercapto-G-arnino-l,3,5-triazine 2,4-Diamino-1,3,5-triazine 2,4-Diamino-6-methy1-l,3,S-triazine 2,4Diamino-6-ethy1l,3,5-trimine 2,4-Diamino-6-n-butyl-l,3,5triazine 2,4-Diamino-S-benzyl-1,3,5triazine 2,4-Dia1nino-6-p-toly1-1,3,fi-triazin 2,4-Diamino-fi-naphthyl-I,3,5-triazinc. 2,4-Diamino fi-cyanoethyl-l,3,5-triazine 2,4-Diamino-6-cyanobutyl-1,3,fi-triazine 2,4-Diamino-6-cyanoocty1-1,3,5-triaziue While our invention has been described with reference to various specific examples and embodiments it will be understood that the invention is not limited to such examples and embodiments and may be variously practiced R1 wherein R and R are selected from the group consisting of hydrogen, alkyl, 'aryl, alkaryl, aralkyl, cyanoalkyl,

pyridyl, amino, hydroxy and mercapto radicals, R and R being unlike radicals when selected from the group consisting of amino, hydroxy and mercapto radicals.

2. The lubricating composition of claim 1 wherein the 1,3,5-triazine compound comprises about to about percent by weight of the total composition.

3. The lubricating composition of claim 1 wherein the lubricating oil is a polyorgano siloxane.

4. The lubricating composition of claim 1 wherein the lubricating oil is a polyphenyl ether.

5. A lubricating composition capable of functioning at temperatures up to about 600 F. consisting of a dispersion in a lubricating oil selected from the group consisting of polyorgano siloxanes, organic esters and polyaryl ethers of a sufficient amount to thicken the lubricating oil to a grease consistency of a guanamine derivative melting above about 205 C. having the following formula:

V N V .Hz H, N /N 7. The lubricating composition of claim 5 wherein the lubricating oil is a polyphenyl ether.

8. A lubricating composition capable of functioning at temperatures up to about 600 F. consisting of a dispersion in a liquid polyorgano siloxane of a suflicient amount to thicken the polyorgano siloxane to a grease consistency of ammeline.

9. A lubricating composition capable of functioning at temperatures up to about 600 F. consisting of a dispersion in a liquid polyorgano siloxane of a suflicient amount to thicken the polyorgano siloxane to a grease consistency of ammelide.

10. A lubricating composition capable of functioning at temperatures up to about 600 F. consisting of a dispersion in a liquid polyphenyl ether of a sufiicient amount to thicken the polyphenyl ether to a grease consistency of ammeline. I

11. A lubricating composition capable of functioning at temperatures up to about 600 F. consisting of a dispersion in a liquid polyphenyl ether of a sufiicient amount to thicken the polyphenyl ether to a grease consistency of ammelide.

12. A lubricating composition capable of functioning at temperatures up to about 600 F. consisting of a dispersion in a liquid polyorgano siloxane of a sufficient amount to thicken the polyorgano siloxane to a grease consistency of a mixture of ammeline and ammelide wherein the weight ratio of ammeline to ammelide is about 1:1.

References Cited in the file of this patent UNITED STATES PATENTS 2,984,624 7 Halter at al. May 16, 1961 

1. A LUBRICATING COMPOSITION CAPABLE OF FUNCTIONING AT TEMPERATURES UP TO ABOUT 600*F. CONSISTIING OF A DISPERSION IN A LUBRICATION OIL SELECTED FROM THE GROUP CONSISTING OF POLYORGANO SILOXANES, ORGANIC ESTERS AND POLYARYL ETHERS OF A SUFFICIENT AMOUNT TO THICKEN THE LUBRICATING OIL TO A GREASE CONSISTENCY OF A 1,3,5-TRIAZINE COMPOUND MELTING ABOVE ABOUT 205*C. HAVING THE FOLLOWING FORMULA: 